html, body {
    margin: 0;
    overflow: hidden;
    font-family: sans-serif;
    background: #13091B;
    height: 100%;
  }
  body {
    background: url(https://p1.music.126.net/gAmIGjlWnYXE_0O8LFp5-w==/109951164382001054.jpg) no-repeat;
    background-size: cover;
  }
  #canvas {
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
  }
  audio {
    visibility: hidden;
  }
  #play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #13091B;
    background: #007A99;
    display: block;
    width: 150px;
    height: 45px;
    line-height: 45px;
    font-size: 18px;
    cursor: pointer;
    border-radius: 4px;
    letter-spacing: 0.1em;
    z-index: 1;
    text-align: center;
    text-decoration: none;
  }
